Structures in TDM range from tudor-style buildings to early Victorian brick buildings. Most buildings have iron pipes running haphazardly up and down walls and floors. Wealthier buildings will have gaslights or electrical lights, while most areas rely on torches and oil lamps.
Coal is the primary source of fuel for larger steam generators, and most larger houses and mansions will have a 'coal room' in the basement where fuel is kept.
Make good use of dirt decals. Most buildings will be covered with grime, and adding dirt decals can make a map feel more realistic and lived in.